Preeti, Gaby

With the help of Ashley Patron's Eqlock script, we calculated the locklosses caused due to EQs for each observing runs. This is a part of the study of investigating the correlation between the microseism and duty-cycle (alog), so we chose winter months (Nov, Dec, Jan and Feb) of each observing run and calculated the vertical velocity of the ground from z-channel and horizontal velocity which is the quadrature sum of x and y channels at the time of locklost due to an EQ. We also did the same study for LLO (alog). 

Conclusion:

• The scatter plots between the peak horizontal velocity and peak vertical velocity during the EQs shows that at Hanford, the horizontal ground motion is more or less similar to the vertical ground motion.
• An attached table has the information about the total number of EQs during each observing runs' winter and the probability of surviving lock during the EQ along with the number of locklosses due to EQ and surviving events. The probability of surviving lock during an EQ for O2 winter was 30%, O3b winter was 54%, O4a winter was 31% and O4b winter was 28%.
• Furthermore, we calculated cumulative distribution function for each observing run and the plot shows the probability of staying lock during EQ events with the horizontal and vertical ground motions has been decreased in O4 winters in compare with O3 winter.